Kaufman & Kleinberg, IADR Abstracts, 1973, No. 444, Page 169, titled "X-Ray Diffraction Study of the Effect of Phytate on the In Vitro Formation of Calcium Phosphate", tested the effect of phytate on the crystallization of calcium phosphate salts and concluded that phytate can inhibit apatite crystallization. The authors commented that this inhibition may suit phytate for preventing formation of dental calculus. This disclosure, however, was based on in vitro conditions and did not take into account in vivo enzymatic hydrolysis. For instance, both fluoride and polycarboxylate are required to provide sufficient inhibition of enzymatic hydrolysis when compounds containing P--O--P bonds are employed against calculus formation, as described in U.S. Pat. No. 4,627,977.
Oral anticaries compositions containing phytate compound and a stannous compound are known, for instance in U.S. Pat. Nos. 4,259,316 and 4,335,102, each to Nakashima et al(Lion Corp.), as well as in Japanese Patent Application Disclosures Nos. 56 095112(1981); 56 075422(1981); 56 045408(1981): 56 039008(1981); and 56 022721(1981); each to Lion Corp. Due to complex formation between polyvalent cations and phytate anion, the presence of stannous compound in an oral composition containing a phytate compound would not be desirable for inhibition of calculus formation.
In U.S. Pat. No. 3,934,002 to Haefele (Proctor & Gamble Co.). Phytic acid is disclosed as one of the anticalculus compounds in oral compositions used together with bis-biguanide antiplaque and anticaries agent. These agents react with one another so that the anticalculus agent would not be homogeneously distributed throughout the oral compositions. Indeed, since both agents are present, if a mouthrinse is prepared, it contains two visibly distinct phases, one being solid phase reaction product of bis-biguanide and anticalculus agent is present. Moreover, if a dentifrice is prepared, it is suggested to avoid an abrasive or polishing agent which adsorbs bis-biguanide compound. Siliceous polishing agents are generally recognized by those knowledgeable in the art as being incompatible with bis-biguanides due to such adsorption. Japanese Patent Application Disclosure No. 61 200905(1986) also describes oral compositions containing chlorhexidine, a bis-biguanide, and phytic acid.
In U.S. Pat. No. 4,193,988 to Forward et al. (Beecham Group Ltd) anticaries oral hygiene compositions are taught containing sodium monofluorophosphate and calcium glycerophosphate wherein calcium phytate may also be present.
In U.S. Pat. No. 4,332,791 to Raaf et al (Blendax-W. Rice), toothpaste is described containing copper compound, one of which may be copper phytate.
In U.S. Pat. Nos. 4,263,270 and 4,305,928, each to Harvey (Colgate-Palmolive Co.) dentifrice containing siliceous polishing agent is described wherein phytic acid prevents color fading when alkali metal monofluorophosphate is present. In an aspect of the inventions described in these patents sodium fluoride may be employed. However, when it is, phytic acid is not used.
In U.S. Pat. No. 4,528,181 to Morton et al (Colgate-Palmolive Co.), phytate is taught to improve fluoride retention in a dentifrice containing a dual source of fluoride (sodium fluoride and sodium monofluorophosphate and a synthetic, precipitated, amorphous silica gel polishing agent. Thus, this patent requires the presence of monofluorophosphate together with phytate.
Belgian Pat. No. 903,498 to Siren provides a detailed disclosure of many inositol triphosphates and includes a brief mention of proposed utilities including possible use as additive in a dentifrice paste. No potential is indicated for HAP inhibition.
Japanese Patent Application Disclosure No. A62 000418(1987) to Lion Corp., Discloses an oral hygiene composition containing hydroxamic acid, a polyphosphoric acid, such as phytic acid, and monofluorophosphoric acid.
In Japanese Patent application Disclosure No. 61 036211(1986) to Lion Corp., sodium and ammonium phytates are disclosed as alternatives to polyphosphates which contain P--O--P bonds, in combination with a compound of a polyvalent metal, particularly magnesium, barium or strontium. Although, it is indicated that the dental composition is intended to reduce calculus formation, the composition admits of complex formation due to the presence of polyvalent metal.
Phytic acid and its derivatives are also described in dentifrices intended to remove dental nicotine stains in Japanese Patent Application Disclosures Nos. 56 018913(1981) describing a dental cleanser and 56 018911(1981), describing a toothpaste, each to Lion Corp. Fluoride is not disclosed, moreover, in the toothpaste of 56 018911, which contains polyvalent cation salt as polishing material.
A tartar preventing chewing gum containing phytate salt is described in Japanese Published Application No. 61 233612(1986) to Kao Corp. Since soluble contents of chewing gums are intended for ingestion fluoride-providing materials are generally to be avoided in chewing gums. They are not disclosed in this patent publication.